Usually at least two conductor tracks (conductor paths) extend parallel to each other on a solar cell (photovoltaic-cell), wherein a pair (2) of conductor tracks connect a first main-surface (upper side) of a solar cell with a second main-surface (lower side) of an adjacent solar cell. A series of solar cells connected in this manner form a so called solar cell string, accordingly providing the following features:                this string comprises a series of solar cells arranged in succession,        adjacent solar cells are connected by at least two electrical conductor tracks,        each conductor track is firmly connected with a first section to an upper surface of a solar cell and with a second section to a lower surface of the adjacent solar cell.        
Usually the conductor tracks have a base body and a solderable coating. The conductor tracks are soldered onto the solar cells.
To process single solar cells with conductor tracks to a complete solar cell string different processing stages and processing steps are necessary. In this context it is essential to ensure an exact positioning of the individual solar cells and the individual conductor tracks, so that also the combination of a multitude of solar cells with a multitude of conductor tracks to form a solar cell string is achieved in the desired and necessary orientation (arrangement). This is difficult inter alia because the solar cells are extremely thin (approximately 200 μm) and brittle and the conductor tracks with a width of for example 0.5 to 3 mm and a thickness of not more than 0.2 to 1 mm are thin strips, which cannot be brought easily into the desired surface contact (fixation) with the upper surface/lower surface of the solar cell.
“Fixing conductor tracks onto a solar cell” according to the invention means the preparatory (preliminary) step to hold the individual conductor track in a defined position on the solar cell (pure support). Independently thereof the fixing includes alternatively and/or cumulatively the physical/chemical fixation (integral connection) of conductor track and solar cell, for example by soldering.
From DE 10 2006 007 447 A1 an installation is known by which solar cells can be fixed onto a carrier belt. An associated hold-down device consists of a frame with bearing surfaces at both its edge sections that are supported by the conveyer belts in the operating position and have a window in which or next to which hold-down heads are arranged that each have a holding-down pin and are mounted pivotable at the frame.
The pins press onto the conductor tracks when the hold-down device is super imposed on the conductor tracks thereby pressing the conductor tracks onto the solar cell, thus fixing them. In this context it is important that the force by which the conductor tracks are being fixed, only takes effect in one direction. The pins are being supported in so called holding-down heads that are hinged pivotably at the frame.
The known hold-down device is constructionally very complex, the pins cause very small pressure-points, whereby the conductor tracks can easily be damaged. Furthermore, an adjustment of the compressive force with respect to the area of the conductor tracks is impossible and can incidentally only be done individually through the holding-down heads. As a result the known solar cell-string has no sufficient surface connection between conductor track and solar cell.